<!DOCTYPE html>  
<html>  
<head>  
  <meta charset="utf-8">  
  <meta http-equiv="X-UA-Compatible" content="IE=edge">  
  <style type="text/css">  
    .mainwrap{  
      margin: 100px auto;  
      height: 300px;  
      border: 1px solid #ff0000;  
    }  
    .left{  
      width: 50%;  
      height: 100%;  
      background: yellow;  
      float: left;  
    }  
    .right{  
      width: 50%;  
      height: 100%;  
      background: pink;  
      float: right;  
      position: relative;  
      top: -100%;  
        
    }  
    .center{  
      width: 600px;  
      margin: 0 auto;  
      height: 100%;  
      background: green;  
      /*float: left;*/  
      position: relative;  
      z-index: 1000;  
    }  
  
  </style>  
</head>  
<body>  
	<!->
	cbd
  <div class="mainwrap">  
      <div class="left"></div>  
      <div class="center">
      	ABCDDDDDDDDDDDDDDDDDDDDDD	
      </div>  
      <div class="right"></div>  
  </div>  
</body>  
</html>  